Hide file-> load toolstrip menu after a load. It kept it open for some reason.

EduNetworkBuilder/NetworkBuilder.cs

@@ -1963,6 +1963,7 @@ namespace EduNetworkBuilder
             if (!File.Exists(mydialog.FileName)) return;
 
             LoadInitialFile(mydialog.FileName);
+            fileToolStripMenuItem.HideDropDown();
         }
 
         private void reloadToolStripMenuItem_Click(object sender, EventArgs e)